1 | #ifndef BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED |
2 | #define BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED |
3 | |
4 | // Copyright 2015, 2016 Peter Dimov. |
5 | // |
6 | // Distributed under the Boost Software License, Version 1.0. |
7 | // |
8 | // See accompanying file LICENSE_1_0.txt or copy at |
9 | // http://www.boost.org/LICENSE_1_0.txt |
10 | |
11 | #include <boost/mp11/integral.hpp> |
12 | #include <boost/mp11/detail/mp_plus.hpp> |
13 | #include <boost/mp11/detail/config.hpp> |
14 | |
15 | namespace boost |
16 | { |
17 | namespace mp11 |
18 | { |
19 | |
20 | // mp_count<L, V> |
21 | namespace detail |
22 | { |
23 | |
24 | #if !defined( BOOST_MP11_NO_CONSTEXPR ) |
25 | |
26 | constexpr std::size_t cx_plus() |
27 | { |
28 | return 0; |
29 | } |
30 | |
31 | template<class T1, class... T> constexpr std::size_t cx_plus(T1 t1, T... t) |
32 | { |
33 | return static_cast<std::size_t>(t1) + cx_plus(t...); |
34 | } |
35 | |
36 | template<class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class... T> |
37 | constexpr std::size_t cx_plus(T1 t1, T2 t2, T3 t3, T4 t4, T5 t5, T6 t6, T7 t7, T8 t8, T9 t9, T10 t10, T... t) |
38 | { |
39 | return static_cast<std::size_t>(t1 + t2 + t3 + t4 + t5 + t6 + t7 + t8 + t9 + t10) + cx_plus(t...); |
40 | } |
41 | |
42 | #endif |
43 | |
44 | template<class L, class V> struct mp_count_impl; |
45 | |
46 | #if defined( BOOST_MP11_HAS_CXX14_CONSTEXPR ) |
47 | |
48 | template<class V, class... T> constexpr std::size_t cx_count() |
49 | { |
50 | constexpr bool a[] = { false, std::is_same<T, V>::value... }; |
51 | |
52 | std::size_t r = 0; |
53 | |
54 | for( std::size_t i = 1; i < sizeof...(T) + 1; ++i ) |
55 | { |
56 | r += a[ i ]; |
57 | } |
58 | |
59 | return r; |
60 | } |
61 | |
62 | template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V> |
63 | { |
64 | using type = mp_size_t<cx_count<V, T...>()>; |
65 | }; |
66 | |
67 | #elif !defined( BOOST_MP11_NO_CONSTEXPR ) |
68 | |
69 | template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V> |
70 | { |
71 | using type = mp_size_t<cx_plus(std::is_same<T, V>::value...)>; |
72 | }; |
73 | |
74 | #else |
75 | |
76 | template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V> |
77 | { |
78 | using type = mp_size_t<mp_plus<std::is_same<T, V>...>::value>; |
79 | }; |
80 | |
81 | #endif |
82 | |
83 | } // namespace detail |
84 | |
85 | template<class L, class V> using mp_count = typename detail::mp_count_impl<L, V>::type; |
86 | |
87 | // mp_count_if<L, P> |
88 | namespace detail |
89 | { |
90 | |
91 | template<class L, template<class...> class P> struct mp_count_if_impl; |
92 | |
93 | #if defined( BOOST_MP11_HAS_CXX14_CONSTEXPR ) && !BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1930 ) |
94 | |
95 | template<template<class...> class P, class... T> constexpr std::size_t cx_count_if() |
96 | { |
97 | constexpr bool a[] = { false, static_cast<bool>( P<T>::value )... }; |
98 | |
99 | std::size_t r = 0; |
100 | |
101 | for( std::size_t i = 1; i < sizeof...(T) + 1; ++i ) |
102 | { |
103 | r += a[ i ]; |
104 | } |
105 | |
106 | return r; |
107 | } |
108 | |
109 | template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P> |
110 | { |
111 | using type = mp_size_t<cx_count_if<P, T...>()>; |
112 | }; |
113 | |
114 | #elif !defined( BOOST_MP11_NO_CONSTEXPR ) |
115 | |
116 | template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P> |
117 | { |
118 | using type = mp_size_t<cx_plus(mp_to_bool<P<T>>::value...)>; |
119 | }; |
120 | |
121 | #else |
122 | |
123 | template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P> |
124 | { |
125 | #if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1920 ) |
126 | |
127 | template<class T> struct _f { using type = mp_to_bool<P<T>>; }; |
128 | using type = mp_size_t<mp_plus<typename _f<T>::type...>::value>; |
129 | |
130 | #else |
131 | |
132 | using type = mp_size_t<mp_plus<mp_to_bool<P<T>>...>::value>; |
133 | |
134 | #endif |
135 | }; |
136 | |
137 | #endif |
138 | |
139 | } // namespace detail |
140 | |
141 | template<class L, template<class...> class P> using mp_count_if = typename detail::mp_count_if_impl<L, P>::type; |
142 | template<class L, class Q> using mp_count_if_q = mp_count_if<L, Q::template fn>; |
143 | |
144 | } // namespace mp11 |
145 | } // namespace boost |
146 | |
147 | #endif // #ifndef BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED |
148 | |